Atara Bio's T-Cell Product Candidate Activated Against Wilms' Tumor 1 Protein Demonstrates Encouraging Results in Patients With Plasma Cell Leukemia

Atara Biotherapeutics, Inc. ATRA, today announced that its collaborating investigators at Memorial Sloan Kettering Cancer Center (MSK) presented clinical data on cytotoxic T lymphocytes (CTL) activated against Wilms' Tumor 1 (WT1-CTL) at the 15th International Myeloma Workshop in Rome, Italy. The WT1-CTL product candidate targets cancers expressing the Wilms Tumor 1, or WT1, antigen. The data is derived from the treatment of patients with relapsed-refractory Multiple Myeloma (MM), including Plasma Cell Leukemia (PCL), with WT1-CTL after allogeneic hematopoietic cell transplantation (alloHCT). Dr. Guenther Koehne, MD, and colleagues, presented the following top-line clinical data from an ongoing phase 1 study: WT1, the tumor associated antigen, was detected on malignant plasma cells in those patients tested. The subjects were treated with alloHCT followed by administration of three infusions of WT1-CTLs. By one year, of seven subjects with relapsed-refractory MM or PCL receiving an alloHCT and treated with WT1-CTLs, three achieved a complete remission (CR), one achieved a partial response (PR), two had stable disease (SD) and one had progressive disease. Adverse events reported were consistent with those typically observed in this transplant population. The details of the poster presentation are below: Title: Wilms' tumor 1 protein See full press release